Buffer system for decelerating a reciprocating gun

ABSTRACT

In a recoil mechanism for a large caliber gun wherein an elongated tapered control rod is fixed in each of a pair of cylinders filled with oil and mounted to the moving parts of the gun for respective slidable engagement with a pair of hollow pistons fixed to a stationary part of the gun and is arranged to enter into the respective pistons during the recoil travel of the moving parts to progressively restrict the flow of fluid therethrough for bringing the parts to a halt, the foregoing structure can also be utilized to halt the moving parts during a portion of the counter-recoil movement thereof simply by providing one of the control rods with a reverse tapered end portion arranged to enter the associated hollow piston with a minimum clearance.

States Patent [151 98,284

Toering et al. 1 Oct. 17, 1972 [54] BUFFER SYSTEM FOR 1,082,717 12/1913 Voller ..89/43 R DECELERATING A RECIPROCATING GUN Primary Examiner-Stephen C. Bentley [72] Inventors: Robert J. Toning Moline, "L; AttorneyHarry M. Saragovitz, Edward J. Kelly, Her- Robert E. Seamands, Bettendorf, Earl and Albert Arnold 57 ABSTRACT [73] Assignee: The United States of America as represented by the Secretary of the In a recoil mechanism for a large caliber gun wherein Army an elongated tapered control rod is fixed in each of a pair of cylinders filled with oil and mounted to the Flledi J y 16, 1970 moving parts of the gun for respective slidable engage- App] No; 55,497 ment with a pair of hollow pistons fixed to a stationary part of the gun and is arranged to enter into the respective pistons during the recoil travel of the mov- [52] U.S.C|. ..89/43 R, 188/289 ing parts to progressively restrict the flow of fluid [51] Illl. Cl. 19/02 therethrough for gi g the parts to a halt h Field Of SGflICh foregoing structure can also be utilized to halt the moving parts during a portion of the counter-recoil [56] References cued movement thereof simply by providing one of the con- UNITED STATES PATENTS trol rods with a reverse tapered end portion arranged 462 970 1 1,189] K 89/43 R to enter the associated hollow piston with a minimum rone clearance 1,883,206 10/1932 Whitted ..188/289 913,349 2/1909 Batault et al. ..188/289 9 Claims, 6 Drawing Figures a 52 cw n l r M. g

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M 3. Q MMW l IN Wllill'llllll A D MH l INVENTORS REL bar J Tnering :BRYEflJETE E 5E1rrnnnfls 2i ATTORNEYS BUFFER SYSTEM FOR DECELERATING A RECIPROCATING GUN The invention described herein may be manufactured, used, and licensed by or for The Government for governmental purposes without the payment to us of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to recoil mechanisms for large caliber guns and is more particularly directed to an oilfilled piston and cylinder arrangement for decelerating the recoiling parts of the gun during a portion of both the recoil and counterrecoil travel thereof.

In hydropneumatic recoil mechanisms for guns of large caliber, the recoil travel of the moving parts is usually halted by throttling a flow of oil through suitable openings in a piston and cylinder type of recoil unit. In order to provide a progressively increasing resistance to the recoil travel of the moving parts, the required throttling of the oil is preferably accomplished by a tapered control rod fixed to the endwall of the cylinder in position to enter into an axial opening in the forward end of the piston. However, since the tapered rod cannot provide any throttling action during the counterrecoil travel of the moving parts, this is usually accomplished by appropriate valve structure which will direct the flow of oil through a separate path containing another throttling mechanism. Obviously, the necessity for separate flow paths each with its own throttling mechanism results in a relatively complicated and costly system, especially in the larger caliber guns.

The complexity of this type of recoil unit is even further increased where the firing cycle of the gun requires that the counterrecoil travel of the moving parts be interrupted to permit the latching thereof in an ammunition loading position. In order to reduce the forces imparted to the latching mechanism at the instant of latching, the counterrecoil energy of the recoiling mass must be substantially nullified in a relatively short period of time without affecting the subsequent ability thereof, following the release of the latch, to reach the predetermined velocity required to initiate firing.

Accordingly, it is an object of this invention to provide a hydropneumatic recoil system for a large caliber gun wherein the rate at which the oil is permitted to flow therethrough can be simply and effectively regulated in both recoil and counterrecoil directions through a single control rod system without the need for separate oil flow paths.

Another object of the present invention lies in the provision of a recoil mechanism, as aforesaid, wherein the flow pressure of the oil in the counterrecoil direction is utilized to inactivate a portion of the flow path therefor to thereby provide the increased throttling action required to halt the travel of the moving parts more rapidly than in the recoil direction thereof.

It is a further object of this invention to provide a recoil system, as aforesaid, which will permit the moving parts to be positively halted in a latched position with a minimum of impact thereon prior to the completion of the full counterrecoil travel required thereof.

It is a more specific object of this invention to provide a recoil system, as aforesaid, wherein the progressively restricted throttling of the oil required to halt the moving parts in the latched position is automatically achieved without detriment to the relatively constant throttling required during the remainder of the counterrecoil travel thereof.

SUMMARY OF THE INVENTION It has been determined that these objects can best be achieved by an oil-filled recoil unit wherein a pair of laterally spaced cylinders are incorporated in the moving parts of the gun to slidably engage the enlarged head portions of correspondingly disposed pistons fixed at one end thereof to a non-recoiling portion of the gun. In order to permit the flow of oil through the entire cylinder, each piston is provided with a suitable passage through the enlarged head thereof. The rate at which the oil is permitted to flow through these passages is controlled by a pair of tapered rods fixed to the cylinder in axial alignment with the hollow pistons for entry therein during the concluding portion of the recoil travel of the moving parts. One of the pistons is provided with a flapper type valve arranged to be held in an open position by the recoil flow of oil through the piston head and to be closed by the return or counterrecoil flow therethrough. The control rod for the particular piston to which the flapper valve is secured is formed with a uniformly decreasing taper along the entire length thereof. However, the other control rod terminates in a reverse-tapered end portion arranged to fit within the hollow interior of the piston with a minimum of clearance therebetween. Thus, as the cylinders ride over the pistons during recoil, oil is forced through the passages in both piston heads to flow toward the recuperator unit. Once the control rods enter the hollow pistons, the tapered configurations thereof act to progressively restrict the flow of oil through the piston heads and thereby provide a portion of the resistance necessary to bring the moving parts to a halt. During the counter-recoil of the moving parts, the flow of oil opposes the opening of the flapper valve thereby preventing the passage of oil through the piston head associated therewith. The resulting decrease in the flow of oil from one end of the cylinder to the other reduces the velocity which would otherwise be imparted to the moving parts. As the reverse tapered end portion of the operative control rod moves through the piston head, the velocity at which the moving parts counterrecoil is even further reduced so that little or no impact force will be transmitted to the latching mechanism. By the time the latching operation is completed, the reverse tapered control rod has moved out of the piston head to unblock the oil passage therethrough and permit the moving parts to continue the required counterrecoil travel thereof subsequent to the release of the latching mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS The exact nature of the invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawings, wherein:

FIG. 1 is a side view of the type of large caliber gun to which the present invention is applicable and is shown with the moving parts in the latched position required thereof during counterrecoil;

FIG. 2 is a transverse section taken along line 2-2 in FIG. 1 showing the dual piston and cylinder arrangement in the recoil unit and the communication between the recoil and the recuperator unit for the flow of oil therebetween;

FIG. 3 is a fragmentary longitudinal section taken along line 3-3 in FIG. 2 showing the relative positions of the pistons and cylinders in the recoil unit at the time the moving parts are in the latched position thereof;

FIG. 4 is a view similar to that of FIG. 3 but showing the flow path of the oil through the cylinders during the counterrecoil travel of the moving parts toward the firing position;

FIG. 5 is a view similar to that of FIG. 3 but showing the flow path of the oil after the moving parts have recoiled to the position at which the control rods have entered the dual pistons; and

FIG. 6 is a view similar to that of FIG. 3 but showing the flow path of the oil during the counterrecoil travel of the moving parts at a time just prior to the completion of latching.

DESCRIPTION OF A PREFERRED EMBODIMENT As best shown in FIG. 1 of the drawings, wherein similar reference characters have been employed to designate corresponding parts throughout, the large caliber gun in which the present invention is incorporated consists of a gun tube 12 and a plurality of yokes l4 longitudinally spaced therealong to secure a recuperator unit 16 and a recoil unit 18 thereto in diametrically opposed relation. Gun tube 12 together with units 16 and 18 are slidably mounted for recoil and counterrecoil movement in a cradle 20 which is, in turn, pivotally supported at the rear end thereof in a suitable stationary mount 22. A lanyard-operated latch 24 is pivotally secured to the side of the cradle 20 in position to normally project into the path of a lug 26 extending laterally from the breech portion of gun tube l2. Latch 24 is arranged to halt the moving parts during the counterrecoil travel thereof to permit the loading of ammunition into gun tube 12. Upon release of latch 24, the moving parts are freed to continue the counterrecoil movement thereof to firing position in response to the energy imparted thereto by the compressed gas in recuperator unit 16.

As best shown in FIG. 3, recoil unit 18 is filled with a hydraulic fluid such as oil and includes a pair of laterally spaced cylinders 28 interconnected at the fore and aft ends thereof, as indicated'at 30 and 32, respectively, to provide passage for the flow of oil therebetween. The aft oil passage 32 also communicates with recuperator unit 16 by means of suitable channels 34 (FIG. 2) extending through the rearmost of yokes 14. Each cylinder 28 is arranged to telescopically surround a hollow piston 36 fixedly secured at the rear end thereof to cradle 20. The opposite and free ends of pistons 36 are provided with enlarged cylindrical heads 38 in slidable contact with the interior wall surfaces of the respective cylinders 28. Immediately to the rear of head 38 thereon, each piston 36 is provided with a plurality of radially spaced ports 40 which communicate with the hollow interior thereof to provide a passage for the flow of oil therethrough.

One of the pistons 36 is equipped with a closure device 42, preferably in the form of a simple flapper valve consisting of a plurality of flapper members 43 secured to piston head 38 in position to block or unblock the flow of oil through parts 40 therein in accordance with the direction in which such flow is being effected. When the oil is forced through piston head 38 and then out through ports 40, the flow pressure forces the flapper members 43 to unblock access to ports 40. However, when the flow is in the opposite direction, the pressure thereof acts against the exterior surfaces of flapper members 43 to block access to ports 40.

The forward endwall of each cylinder 28 is provided with an elongated and tapered control rod fixed thereto in respective axial alignment with pistons 36 as indicated at 44 and 46. Control rod 44 is in alignment with the piston 36 to which closure device 42 is attached and is tapered along the entire exterior thereof such that the diameter thereof is a maximum at the point of contact with the end wall of cylinder 28. Such maximum diameter is equivalent to the diameter of the hollow interior of piston 36. Although the other control rod 46 is dimensionally identical to rod 44 at the point of attachment to cylinder 28, the taper of the former proceeds at a steeper pitch to a point approximately two-thirds along the length thereof. At that point, such decreasing taper is reversed as shown at 48, to provide a progressively increasing diameter along the remaining length thereof. The diameter at the free end of rod 46 is slightly smaller than the corresponding diameter within the hollow interior of piston 36 and is preferably dimensioned to provide a clearance of about 0.005 inch. The passage of oil into the hollow interior of each piston 36 is halted by a plug 50 fixed therein at a point slightly in excess of the length of rods 44 and 46. In addition, a plurality of relief outlets 52 are provided adjacent the rear face of plug 50, as shown in FIG. 3, in the particular piston associated with control rod 46.

Thus, when latch 24 is released, the compressed gas in recuperator unit 16 will accelerate the moving parts toward the firing position thereof. As cylinders 28 move forwardly relative to stationary pistons 36, the oil between the rear endwalls of cylinders 28 and piston heads 38 is forced to flow in a forward direction as indicated by the arrows in FIG. 4. Since such flow actuates closure device 42 to block off ports 40 in the piston 36 associated therewith, the entire transfer of oil from the rearward to the forward areas of cylinders 28 is limited to ports 40 in the other piston 36 and consequently provides the required increase in resistance to the counterrecoil travel of the moving parts.

When the gun is fired, the direction of travel of the moving parts and consequently that of the oil flow is reversed. Since such flow is directed through piston heads 38 prior to passage through ports 40, closure device 42 is opened so that ports 40 in both pistons 36 are fully utilized. As control rods 44 and 46 enter into the hollow interiors of pistons 36, the oil passage area through heads 38 is substantially reduced, as best shown in FIG. 5, and continues to be reduced in accordance with the increasing diameters of such rods to bring the moving parts to a halt. The diameters and the degree of taper of rods 44 and 46 are designed so that once entry thereof into piston heads 38 has been initiated, the resulting annular oil passage therethrough will provide the total area necessary to control the deceleration of the moving parts in a predetermined progressively increasing fashion. Once the end of control rod 46 passes beyond ports 40 in piston 36, the oil ports 40 adjacent thereto and thereby limit the passage for the oil to the particular piston head 38 associated with control rod 46. Since the decreasing taper on rod 46 provides a corresponding increase in the annular oil passage through piston head 38, the counterrecoil travel of the moving parts begins to accelerate. However, once the reverse tapered portion 48 of control rod 46 reaches piston head 38, the ensuing reduction in the annular oil passage area therethrough provides a corresponding deceleration in the counterrecoil velocity of the moving parts. Such deceleration reaches a maximum when control rod 46 is in the position shown in PK). 6 and, consequently, permits latch 24 to halt the moving parts of the gun with a minimum im pact.

Thus, there is here provided a relatively simple yet highly efficient system for throttling the flow of oil through a recoil unit so as to control the recoil and counterrecoil decelerations required of the moving parts in a large caliber gun wherein such parts must be halted in a stationary position prior to the completion of counterrecoil. The reduced rate of oil flow required during counterrecoil is automatically provided without the necessity for the separate flow path customarily utilized in the recoil systems of the prior art. As a result, the relatively complicated valving heretofore required to provide a more restricted flow of oil in the counterrecoil direction can be replaced by a single closure device operatively responsive to the direction in which the hydraulic fluid or oil is forced to flow through the recoil unit. Consequently, the moving parts can be decelerated in both directions of movement thereof with no additional moving parts and with no increase in the overall size thereof.

Although the present invention is explained in accordance with the preferred embodiment shown and described herein, it will also become obvious to persons skilled in the art that other forms thereof as well as changesin the particular forms described, are possible within the spirit and scope of the present invention. Therefore, it is desired that the present invention shall not be limited except insofar as it is made necessary by the prior art and by the spirit of the appended claims.

We claim:

ll. In a hydropneumatic recoil mechanism for large caliber guns wherein the moving parts thereof include a pair of oil-filled cylinders disposed in respective slidable engagement with a pair of stationary pistons, means for decelerating the moving parts during a portion of both the recoil and the counterrecoil travel thereof comprising,

passage means in each of the pistons for the flow of oil therethrough during the slidable movement of said cylinders,

closure means on one of the pistons responsive to the flow of oil in the cylinders for blocking such flow through said one piston during the counterrecoil travel of the moving parts,

a pair of elongated tapered control rods fixed at one end thereof in the cylinders in respective axial alignment with said passage means through the pistons whereby the flow of oil therethrough during the recoil travel of the moving parts is progressively restricted to assist in bringing the latter to a halt, and

a reverse tapered end portion on the one of said rods in alignment with said passage means in the other one of said pistons whereby the flow of oil therethrough during the counterrecoil travel of the moving parts is progressively restricted to assist in bringing the latter to a halt. it

2. The combination defined in claim 1 wherein said closure means comprises a plurality of flapper members secured to the exterior periphery of the said one of the pistons in position to be actuated by the flow of oil through the cylinders for opening and closing said passage means therein in accordance with the direction of the oil flow.

3. The combination defined in claim 1 wherein said control rod with said reverse tapered end portion comprises,

a first section of decreasing taper from the point of attachment thereof to the cylinder to a point substantially two-thirds along the length thereof, and

a second section of increasing taper extending integrally from said first section.

4. The combination defined in claim 1 wherein said passage means in each of the pistons includes,

an axial opening in the end facing said control rod,

and

a plurality of ports radially spaced about the periphery of each of the pistons in direct communication with said axial opening therein.

5. The combination defined in claim 4 wherein said axial openings in the pistons extend rearwardly beyond said ports therein to a distance greater than the lengths of said control rods, and wherein the piston other than the said one piston is provided with a plurality of relief outlets at the end of said axial opening therein for the oil displaced by the reverse tapered end portion of said control rod during the movement of said cylinders in the counterrecoil direction.

6. The combination defined in claim 4 wherein the maximum diameter of said reverse tapered end portion on said control rod therewith provides a clearance fit with said axial opening in the associated piston.

7. In a hydropneumatic recoil mechanism for large caliber guns wherein the moving parts are temporarily latched during the counterrecoil travel thereof to permit the loading of ammunition, means for decelerating the moving parts during recoil and during the portion of the counterrecoil movement prior to the attainment of the latched position thereof, comprising,

a pair of hollow pistons fixed at one end thereof to a non-recoiling portion of the gun,

a pair of oil-filled cylinders incorporated in the moving parts in respective slidable engagement with said pistons,

passage means in each of said pistons to permit the flow of oil through said cylinders during the movement thereof relative to said pistons,

closure means pivotally mounted on one of said pistons adjacent said passage means therein in position to be actuated by the flow of oil through said cylinders for opening and closing said passage means in said one of said pistons in accordance with the direction of movement of the moving parts,

an elongated tapered control rod fixed at one end thereof in each of said cylinders in axial alignment with said passage means in said pistons for progres- 10 sively restricting the flow of oil therethrough during movement of the moving parts in the recoil direction, and

a reverse tapered end portion on the one of said con trol rods in axial alignment with said piston other than said one with said closure means whereby the flow of oil through said passage means in said other one of said pistons is progressively restricted during the counterrecoil movement of the moving parts toward the latched position thereof.

8. The combination defined in claim 7 wherein said pistons terminate in enlarged head portions slidably engageable with said cylinders, and wherein said passage means in said pistons includes a plurality of radially disposed ports through the walls thereof adjacent said enlarged head portions thereon.

9. The combination defined in claim 8 wherein a plug is fixed in each of said hollow pistons at a distance from said enlarged head portions thereon greater than the length of said control rods, and said other one of said pistons also includes a plurality of relief ports adjacent the forward end of said plug therein to permit the passage of the oil displaced by the movement of said reverse tapered end portion into said passage means therein during the recoil travel of the moving parts. 

1. In a hydropneumatic recoil mechanism for large caliber guns wherein the moving parts thereof include a pair of oil-filled cylinders disposed in respective slidable engagement with a pair of stationary pistons, means for decelerating the moving parts during a portion of both the recoil and the counterrecoil travel thereof comprising, passage means in each of the pistons for the flow of oil therethrough during the slidable movement of said cylinders, closure means on one of the pistons responsive to the flow of oil in the cylinders for blocking such flow through said one piston during the counterrecoil travel of the moving parts, a pair of elongated tapered control rods fixed at one end thereof in the cylinders in respective axial alignment with said passage means through the pistons whereby the flow of oil therethrough during the recoil travel of the moving parts is progressively restricted to assist in bringing the latter to a halt, and a reverse tapered end portion on the one of said rods in alignment with said passage means in the other one of said pistons whereby the flow of oil therethrough during the counterrecoil travel of the moving parts is progressively restricted to assist in bringing the latter to a halt.
 2. The combination defined in claim 1 wherein said closure means comprises a plurality of flapper members secured to the exterior periphery of the said one of the pistons in position to be actuated by the flow of oil through the cylinders for opening and closing said passage means therein in accordance with the direction of the oil flow.
 3. The combination defined in claim 1 wherein said control rod with said reverse tapered end portion comprises, a first section of decreasing taper from the point of attachment thereof to the cylinder to a point substantially two-thirds along the length thereof, and a second section of increasing taper extending integrally from said first section.
 4. The combination defined in claim 1 wherein said passage means in each of the pistons includes, an axial opening in the end facing said control rod, and a plurality of ports radially spaced about the periphery of each of the pistons in direct communication with said axial opening therein.
 5. The combination defined in claim 4 wherein said axial openings in the pistons extend rearwardly beyond said ports therein to a distance grEater than the lengths of said control rods, and wherein the piston other than the said one piston is provided with a plurality of relief outlets at the end of said axial opening therein for the oil displaced by the reverse tapered end portion of said control rod during the movement of said cylinders in the counterrecoil direction.
 6. The combination defined in claim 4 wherein the maximum diameter of said reverse tapered end portion on said control rod therewith provides a clearance fit with said axial opening in the associated piston.
 7. In a hydropneumatic recoil mechanism for large caliber guns wherein the moving parts are temporarily latched during the counterrecoil travel thereof to permit the loading of ammunition, means for decelerating the moving parts during recoil and during the portion of the counterrecoil movement prior to the attainment of the latched position thereof, comprising, a pair of hollow pistons fixed at one end thereof to a non-recoiling portion of the gun, a pair of oil-filled cylinders incorporated in the moving parts in respective slidable engagement with said pistons, passage means in each of said pistons to permit the flow of oil through said cylinders during the movement thereof relative to said pistons, closure means pivotally mounted on one of said pistons adjacent said passage means therein in position to be actuated by the flow of oil through said cylinders for opening and closing said passage means in said one of said pistons in accordance with the direction of movement of the moving parts, an elongated tapered control rod fixed at one end thereof in each of said cylinders in axial alignment with said passage means in said pistons for progressively restricting the flow of oil therethrough during movement of the moving parts in the recoil direction, and a reverse tapered end portion on the one of said control rods in axial alignment with said piston other than said one with said closure means whereby the flow of oil through said passage means in said other one of said pistons is progressively restricted during the counterrecoil movement of the moving parts toward the latched position thereof.
 8. The combination defined in claim 7 wherein said pistons terminate in enlarged head portions slidably engageable with said cylinders, and wherein said passage means in said pistons includes a plurality of radially disposed ports through the walls thereof adjacent said enlarged head portions thereon.
 9. The combination defined in claim 8 wherein a plug is fixed in each of said hollow pistons at a distance from said enlarged head portions thereon greater than the length of said control rods, and said other one of said pistons also includes a plurality of relief ports adjacent the forward end of said plug therein to permit the passage of the oil displaced by the movement of said reverse tapered end portion into said passage means therein during the recoil travel of the moving parts. 